Floating type disk brake

Abstract

A floating type disc brake “A” used for a vehicle such as a motorcycle comprising a braking rotor 1 A and a hub 2 A arranged inside the braking rotor 1 A, the braking rotor 1 A including an annular rotor portion 11 and a plurality of projections 13 A extending radially inward from the inner circumferential portion of the rotor portion 11 , and further comprising a connecting means 3 for connecting the braking rotor 1 A and the hub 2 A at positions in which the projections 13 A of the braking rotor 1 A are abutted to the outer circumferential portion of the hub 2 A. At least one of the rotor portion 11 and the projections 13 A is formed with cutout portions 13 b at the boundary region between the rotor portion 11 and the projections 13 A. It is possible to suppress a local heat dissipation in regions of the rotor portion 11 in which the projections 13 A are formed and thus to reduce irregularity of heat distribution in the rotor portion 11 during braking operations.

1. A floating type disc brake, comprising
 a braking rotor and a hub arranged inside the braking rotor, the braking rotor including an annular rotor portion and a plurality of projections extending radially inward from the inner circumferential portion of the rotor portion, 
 a connecting means for connecting the braking rotor and the hub at positions wherein the projections of the braking rotor are abutted to the outer circumferential portion of the hub, and 
 cutout portions located peripherally on respective sides of each of the projections adjacent a boundary region between the rotor portion and the projections, such that a minimum width between the respective sides of each of the projections, measured at a portion at which the cutout portions are formed, is smaller than a width at a radially inner end of each of the projections, 
 wherein each of the respective sides of the projections includes a convex portion located radially between the radially inner end and each of the cutout portions. 
 
     
     
       2. The floating type disc brake of  claim 1  wherein the cutout portions are symmetrically formed at either side of each projection. 
     
     
       3. The floating type disc brake of  claim 1  wherein each cutout portion is formed by a curved outline to avoid stress concentration. 
     
     
       4. The floating type disc brake of  claim 1  wherein the rotor portion is formed with an opening at the boundary region between the rotor portion and the projections and the connecting means has a center and the opening has a center and the centers lie on a common radius of the braking rotor. 
     
     
       5. The floating type disc brake of  claim 1 ,
 wherein the hub has straight beam-like portions connecting circumferential portions of the hub abutted to the projections of the braking rotor, and that the longitudinal center line of each beam-like portion is positioned radially inside of an imaginary line connecting between the connecting means. 
 
     
     
       6. The floating type disc brake of  claim 1  wherein the connecting means includes a first plurality of pressing plates, a second plurality of pressing plates, and a plurality of leaf springs,
 wherein the second plurality of pressing plates are arranged opposite to a respective one of the first plurality of pressing plates and sandwiching therewith a respective one of the plurality of projections, and the each of the first plurality of pressing plates includes a plate portion and a pair of cylindrical legs extending from the plate portion, and each of the second plurality of pressing plates includes a second plate portion, a pair of openings in the second plate portion that receive a respective one of the pair of legs, and a shallow groove that receives the leaf spring. 
 
     
     
       7. A floating type disc brake, comprising:
 a braking rotor and a hub arranged inside the braking rotor, the braking rotor including an annular rotor portion and a plurality of projections extending radially inward from the inner circumferential portion of the rotor portion, 
 a connecting means for connecting the braking rotor and the hub at positions wherein the projections of the braking rotor are abutted to the outer circumferential portion of the hub, and 
 cutout portions which reduce a contacting area between the rotor portion and each projection are formed at positions radially aligned with the connecting means and facing toward the border of the projections and the rotor portion. 
 
     
     
       8. A floating type disc brake comprising;
 a braking rotor and a hub arranged inside the braking rotor, the entire surface of the braking rotor in its axial direction being formed with a plurality of circular through apertures, 
 wherein the plurality of through apertures are distributed on a plurality of first circles having predetermined different radii concentric with the braking rotor, the distribution being made such that, on second circles, each having a predetermined radius from a center of any one of the through apertures positioned on any one of the first circles, two other through apertures positioned on another of the first circles are positioned, 
 
       wherein the second circles have the same radius relative to all the through apertures, and wherein the two other through apertures are the closest ones to the any one of the through apertures. 
     
     
       9. The floating type disc brake of  claim 8  wherein at least one of the inner and outer circumferential portions of the braking rotor is formed with substantially semi-circular cutouts. 
     
     
       10. The floating type disc brake of  claim 8  wherein the edge portions of the through apertures are arranged so that they are positioned at or near mutually adjacent the first circles. 
     
     
       11. The floating type disc brake of  claim 8  wherein the braking rotor comprises an annular rotor portion and a plurality of projections spaced apart each other and extending radially inward from the inner circumferential portion of the rotor portion, wherein the outer circumferential portion of the hub is formed with cutouts corresponding to the projections of the braking rotor, and wherein constricting means for preventing axial separation between the braking rotor and the hub are arranged at regions in which the projections are fitted in the cutouts when the hub is arranged inside the braking rotor. 
     
     
       12. The floating type disc brake of  claim 11  wherein cutout portions are symmetrically formed at both radially extending sides of each projection. 
     
     
       13. The floating type disc brake of  claim 11  wherein the through apertures are formed in a projected region of the projections to the rotor portion at positions apart a distance larger than the thickness of the rotor portion from the boundary between the rotor portion and the projections. 
     
     
       14. The floating type disc brake of  claim 12  wherein the through apertures of the braking rotor are arranged symmetrically with respect to a radial line passing through the center of one of projections and the center of rotation of the braking rotor. 
     
     
       15. The floating type disc brake of  claim 5  wherein the longitudinally middle point of each beam-like portion is positioned radially outside a middle point of a radial line connecting the inner circumferential portion of the rotor portion and the outer circumferential portion of a central opening formed in the hub. 
     
     
       16. The floating type disc brake of  claim 5  wherein the hub is formed with linear arms extending radially outward from the central opening of the hub so that they are abutted to the projections of the braking rotor. 
     
     
       17. The floating type disc brake of  claim 11  wherein the constricting means includes a first plurality of pressing plates and a second plurality of pressing plates arranged opposite to a respective one of the first plurality of pressing plates and sandwiching therewith a respective one of the plurality of projections, wherein the each of the first plurality of pressing plates includes a plate portion and a pair of cylindrical legs extending from the plate portion, and each of the second plurality of pressing plates includes a second plate portion and a pair of openings in the second plate portion that receive a respective one of the pair of legs.